There are a couple of notable new features--including an "Explore" search bar and a focus on "Channels"--as well as a new, streamlined layout with lots of bright pictures. StumbleUpon also has a new logo--a modern, red-and-white design, completely different from its familiar blue-and-green logo.

If you head on over to StumbleUpon and check out your homepage, you'll see that the new design sports the new logo as well as a simpler layout. Your homepage now features the categories you're interested in, along with relevant pictures.

There's also an "Explore" box in the top right corner. The Explore box, which has been in beta since August, is a glorified search box. If you start typing in a search term or phrase, you'll be presented with a drop-down menu of terms/phrases to choose from. Choose the relevant phrase (or just hit enter) and you'll be able to "stumble" through pages that are related to that particular phrase. The Explore box basically lets you stumble through more specific categories (for example, you can stumble through "Paris"-related pages, rather than the general category of "Travel").

Another new feature that StumbleUpon's redesign highlights is "Channels." Like YouTube, who redesigned its site last week, StumbleUpon is also focusing on curated content rather than completely random stumbling. StumbleUpon's Channels feature allows you to follow people, Websites, and brands--but unlike a regular newsfeed, you're only subject to updates that are relevant to categories you're interested in. So, for example, if you want to follow Lady GaGa's music--but not her animal rights' campaigns or crazy sense of fashion--now you can.

Channels can be added and accessed from your StumbleUpon profile page. Current "Recommended Channels" include DETAILS Magazine, Gilt City, CNN, and Epicurious.